In general, a vehicle is installed with air conditioning equipment, in which an air duct having an air movement path is provided such that an air conditioner and a heater are mounted so as to circulate and purify the room air and outside air or maintain the temperature of a vehicle room.
Air vents connected to the discharge parts of the air duct are provided to panels in a vehicle room so as to be used for discharging the air from the air conditioner or the heater towards a driver and passengers in desired directions such that the driver or the passengers can enjoy travelling of cool or warm comfort.
The air vent as described above typically includes an air vent housing provided with an air path, a damper for opening or closing the air path of the air vent housing and a knob for operating the damper.
There have been suggested constituent elements for rotating the damper by operating the knob, as shown in FIG. 1, wherein intermediate stems 2, each having a gear formed at one side so as to be engaged with the path of a duct 5, rotate in the duct 5 by the operations of a main lever 3 and an auxiliary lever 4 so as to carry out opening and closing the path.
However, the prior art damper device has a problem in the operation thereof since deformation and bending are apt to be generated more as long as the lengths of the main lever and the auxiliary lever. Therefore, it is difficult to accurately transmit a stroke, thereby resulting in the failure of the rotation operation of the damper and the decrease of airtightness performance.